From Seven Seas:

Higuchi Kotarou was just a normal sixth-grader until a new next-door neighbor enters his life--an insanely perky angel named Misha that has made it her life's work to make Kotarou happy! And if that wasn't enough, Misha has an even stranger roommate--a kind-hearted demon named Shia and her mysterious black cat Nya! If Kotarou's life at home is this weird, what can it possibly be like at school? Find out in these fun-filled, brand-new adventures that reveal the origins of Koge-Donbo's beloved characters first introduced in the hit Pita-Ten manga series!